McAllister, Wallace R.||McAllister, Dorothy E.
M.A. (Master of Arts)
Department of Psychology
Fear||Extinction (Psychology)||Association of ideas||Conditioned response
It has been demonstrated that the presentation of an unconditioned stimulus (UCS) will result in an increment in the level of responding to an extinguished conditioned stimulus (CS) which had previously been paired with the UCS. Possible explanations for this reinstatement phenomenon have implicated either associative or nonassociative mechanisms. The nonasso- ciative interpretation holds that reinstatement results from an increase in the representation of the UCS that had been devalued during extinction. The associative model assumes that reinstatement is the product of the reconditioning of the conditioned response (CR) to the stimuli present at the time of the UCS presentation. In this study, 112 rats received handling and exploration of a hurdle-jumping apparatus on Day 1. On Day 2, five groups received 25 trials in which fear was conditioned to the stimuli of one compartment of the hurdle-jumping apparatus (white box with grid floor) followed by the extinction of fear to those apparatus cues. Two other groups spent an equal amount of time during these periods in a neutral box. Shock presentations were then administered in either the testing context (hurdlejumping apparatus), the testing context in darkness (no visual cues), or in a distinctly different context (small, solid-floor box), in an attempt to reinstate the extinguished fear response. On Day 3, the amount of fear elicited by the situational cues of the hurdle-jumping apparatus was measured by the learning of an escape-from-fear task. The results clearly support an associative reconditioning model. Reinstatement was obtained only when some further conditioning of the CR (fear) to the CS took place. Groups given UCS presentations in the solid-floor box showed no evidence of reinstated fear, therefore providing data contrary to a non- associative model of reinstatement. When reinstatement shocks were presented in darkness, subjects performed as well as those given the shocks, in the original context. This finding demonstrates the dominance of the tactual over the visual cues in the reinstatement situation.
Callen, Edward J., "Associative and nonassociative factors in the reinstatement of extinguished fear" (1982). Graduate Research Theses & Dissertations. 1557.
vii, 51 pages
Northern Illinois University
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